Some aspects of the interplay between bipartite correlations and quantum channels

TL;DR

This thesis investigates how quantum channels and correlations interact in various physical contexts, focusing on their roles in system dynamics, entanglement robustness, and the relationship between nonclassicality and entanglement breaking.

Contribution

It provides new insights into the interplay between quantum correlations and channels, including the effects of initial correlations, correlation measures for X-states, and properties of bosonic Gaussian channels.

Findings

Initial system-bath correlations influence subsystem dynamics.

Correlation measures for two-qubit X-states are computed.

Non-Gaussian entanglement shows robustness under certain noisy channels.

Abstract

This thesis explores ways in which quantum channels and correlations (of both classical and quantum types) manifest themselves, and also studies the interplay between these two aspects in various physical settings. Quantum channels represent all possible evolutions of states allowed by quantum mechanics while correlations are intrinsic (nonlocal) properties of composite systems. There are four main problems that are addressed (i) the role played by initial system-bath correlations on the subsystem dynamics of an open quantum system, (ii) computation of correlations for two-qubit X-states, (iii) the robustness of non-Gaussian entanglement under symmetric local noisy attenuator and amplifier channels, and finally, (iv) the connection between nonclassicality breaking and entanglement breaking for single-mode bosonic Gaussian channels.